welkman001 11:02am, 20 November 2011
Hi all,

I have done a bit of prodding around and have discovered a few extra jobs for the list this weekend. One of them is to sort out the tiller stock attatchment which had a lot of play. If you see the pics in my photostream there are two of the rudder stock. The fitting is circular and has a pinch bolt at the back and a large bolt at the front. The pinch bolt is totally screwwed in and if I adjust the large bolt the play goes away. Im not sure this will be a very safe arrangment ? Do you think it will be ok for next season providing I keep an eye on it?

Also have a look at the pics of the 'bog of doom' while your there!
Cheers

James
busy home [deleted] 7 years ago
No replace it ,,, see reply on photo.
Polishing the mast is next years job ,,
Never ignore steering or brakes
welkman001 7 years ago
Interesting weekend. Had a bit of a look at the soft spot on the cabin roof and have found most of the balsa to be saturated. I have decided to grind off the inner skin, remove the exsisting balsa and replace with closed cell foam, finishing with two coats of class cloth. I am going to try doing nice small bits of foam to keep it managable.

Other than the roof I have removed the locker sides, sink and skin fitting, tried the electronics and found the instruments to be knackered also I have had a go at getting the old log off the hull with no success.

Has anyone had a stab at core replacment on the scale I am going for? Any tips for removing the log from the hull? Are there any other areas to look at re delamination of the cored decks?

Was up at the crack of dawn to help a good freind get his new project moved today, see photo stream, puts my core replacment into perspective!

Cheers,

James
rothwell_neil 7 years ago
James

Just a word, the balsa acts as a spacer and as it is stiff increases the strength by bracing between the two glass layers, used to be used in end grain to work structurally. Thus would think about ply or wood rather than common closed cell foam unless you have access to any Rohacell as this is ideal for laminating as it is hard and can be machined and sanded to shape. I wouldn't use anything less stiff but this stuff is expensive but it does the job. Balsa would be cheaper than Rohacell.
Skykomish E29 7 years ago
I agree with Neil. In PBO a while back, when they replaced the deck of a motorboat that had de laminated they used ply as the core material with epoxy. They "scored" the ply so that it conformed to the shape of the deck then coated liberally with epoxy to strengthen before replacing the skin.
welkman001 7 years ago
sounds like a good plan. The foam I was going to use was proper structural foam at 460kg/M^3 density but ply certainly would be cheaper. I redid the decks of my old 1/4 tonner in sheaved ply. When you say 'scored' do you mean routed to give a better surface area? Do you reckon you need to use marine ply or exterior ply?
Skykomish E29 7 years ago
No, Scored as in cutting ALMOST through the wood so that it folds to the contours of the roof I shall try and find the article.
Personally I would say that Exterior ply would be adequate as it is going to be skimmed with epoxy so will be sealed in place, the original balsa was certainly not waterproof
Mick G N 7 years ago
Silly question for you - What is the consequence of doing nothing about a soft spot in the roof?

As you may know we have a similar problem on Picaroona, we think and hope that we have found and sorted the source of water ingress but now face the challange or not of tackling the balsa!
Skykomish E29 Posted 7 years ago. Edited by Skykomish E29 (member) 7 years ago
I think it really depends on where the soft spot is and how big it is. If it isn't in a structural part of the boat or one subjected to severe stress, i.e. the mast foot then as long as the leak is cured, not a great problem, though I would imagine the area around the soft spot will be subject to gel coat cracking through flexion. I would suggest at the very least a "drain" hole should be drilled at the lowest point so that the core can dry out, then if it is localised rot, drill into the core from the top side and inject epoxy to replace the rotted fibres and fill the void. However this is just based on what I have read in manuals on this subject, I am not an authority on this and no doubt others will have their own ideas.
The PBO article relating to repairing a cored deck is in the MAy 2009 issue number 509
WELKMAN: check your Flickr Mail I have sent you a message
rothwell_neil 7 years ago
How big a spot is it? If a small area up to 6" diameter I would consider drilling holes, using bent wire in a drill to remove old balsa, suck it out, then fill with epoxy and microballoons from hole in deck with holes in bottom taped over. Used to do this on my old windsurfers when they delaminated.
welkman001 7 years ago
Hi Neil,

Unfortunatley there is only about a 6" diameter patch of good core left! Ireckon it will be easier to cut the whole lot out and start again.
rothwell_neil 7 years ago
Sounds like a sheet of ply then
Skykomish E29 7 years ago
James e mail sent to you
Mick G N 7 years ago
Thanks for the "heads up", we will most likley leave well enough alone but that said we have a former boat builder coming down to take a look at the damage.

How nice it would be to have a dry boat!!!!
Daddsie 7 years ago
Had a large soft spot alongside the starboard chain plates, cut out the defective area and cleared up the damaged balsa. glassed it all back in. Getting the finish right has proved to be very awkward
craig48uk 7 years ago
So glad Chiron is solid glass, so much easier!
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